Hello.
syzbot is reporting that iforce_close() from input_close_device() from
joydev_close_device() from joydev_release() forever sleeps at
wait_event_interruptible(iforce->wait,
!test_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags));
with dev->mutex held, which in turn prevents input_disconnect_device() from
__input_unregister_device() from input_unregister_device() from
iforce_usb_disconnect() from setting dev->going_away = true.
We somehow need to wake up this wait_event_interruptible() in iforce_close()
if iforce_usb_disconnect() is in progress. But iforce_usb_disconnect() does
not manipulate flags for waking up this wait_event_interruptible(). How can
we wake up this wait_event_interruptible()?
INFO: task kworker/0:0:6 blocked for more than 143 seconds.
Not tainted 5.18.0-syzkaller-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0 state:D stack:24464 pid: 6 ppid: 2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5073 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388
schedule+0xd2/0x1f0 kernel/sched/core.c:6460
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6519
__mutex_lock_common kernel/locking/mutex.c:673 [inline]
__mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:733
input_disconnect_device drivers/input/input.c:784 [inline]
__input_unregister_device+0x24/0x470 drivers/input/input.c:2236
input_unregister_device+0xb4/0xf0 drivers/input/input.c:2431
iforce_usb_disconnect+0x5e/0xf0 drivers/input/joystick/iforce/iforce-usb.c:261
usb_unbind_interface+0x1d8/0x8e0 drivers/usb/core/driver.c:458
device_remove drivers/base/dd.c:532 [inline]
device_remove+0x11f/0x170 drivers/base/dd.c:524
__device_release_driver drivers/base/dd.c:1200 [inline]
device_release_driver_internal+0x4a3/0x680 drivers/base/dd.c:1223
bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:529
device_del+0x4f3/0xc80 drivers/base/core.c:3592
usb_disable_device+0x35b/0x7b0 drivers/usb/core/message.c:1419
usb_disconnect.cold+0x278/0x6ec drivers/usb/core/hub.c:2228
hub_port_connect drivers/usb/core/hub.c:5207 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5507 [inline]
port_event drivers/usb/core/hub.c:5665 [inline]
hub_event+0x1e74/0x4680 drivers/usb/core/hub.c:5747
process_one_work+0x996/0x1610 kernel/workqueue.c:2289
process_scheduled_works kernel/workqueue.c:2352 [inline]
worker_thread+0x854/0x1080 kernel/workqueue.c:2438
kthread+0x2e9/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>
6 locks held by kworker/0:0/6:
#0: ffff8881457f4138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff8881457f4138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff8881457f4138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff8881457f4138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
#0: ffff8881457f4138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
#0: ffff8881457f4138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x87a/0x1610 kernel/workqueue.c:2260
#1: ffffc900000b7da8 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x1610 kernel/workqueue.c:2264
#2: ffff88801f817220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:767 [inline]
#2: ffff88801f817220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4680 drivers/usb/core/hub.c:5693
#3: ffff88814bc3b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:767 [inline]
#3: ffff88814bc3b220 (&dev->mutex){....}-{3:3}, at: usb_disconnect.cold+0x43/0x6ec drivers/usb/core/hub.c:2219
#4: ffff88814bc3a1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:767 [inline]
#4: ffff88814bc3a1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1033 [inline]
#4: ffff88814bc3a1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa0/0x680 drivers/base/dd.c:1220
#5: ffff88807b7202c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_disconnect_device drivers/input/input.c:784 [inline]
#5: ffff88807b7202c0 (&dev->mutex#2){+.+.}-{3:3}, at: __input_unregister_device+0x24/0x470 drivers/input/input.c:2236
task:acpid state:S stack:23384 pid: 2951 ppid: 1 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5073 [inline]
__schedule+0xa9a/0x4cc0 kernel/sched/core.c:6388
schedule+0xd2/0x1f0 kernel/sched/core.c:6460
iforce_close+0x396/0x4b0 drivers/input/joystick/iforce/iforce-main.c:203
input_close_device+0x156/0x1f0 drivers/input/input.c:734
joydev_close_device drivers/input/joydev.c:223 [inline]
joydev_release+0x222/0x290 drivers/input/joydev.c:252
__fput+0x277/0x9d0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:169 [inline]
exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f135bd3ffc3
RSP: 002b:00007ffe571c93d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007ffe571c9648 RCX: 00007f135bd3ffc3
RDX: 00007ffe571c8808 RSI: 000000000000001e RDI: 000000000000000a
RBP: 000000000000000a R08: 00007ffe571c965c R09: 00007ffe571c9548
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe571c9548
R13: 00007ffe571c9648 R14: 0000000000000020 R15: 0000000000000000
</TASK>
2 locks held by acpid/2951:
#0: ffff88807bd28158 (&joydev->mutex){+.+.}-{3:3}, at: joydev_close_device drivers/input/joydev.c:220 [inline]
#0: ffff88807bd28158 (&joydev->mutex){+.+.}-{3:3}, at: joydev_release+0x187/0x290 drivers/input/joydev.c:252
#1: ffff88807b7202c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_close_device+0x42/0x1f0 drivers/input/input.c:726
On 2022/07/02 14:32, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: a175eca0f3d7 Merge tag 'drm-fixes-2022-07-01' of git://ano..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=17141c97f00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=3a010dbf6a7af480
> dashboard link: https://syzkaller.appspot.com/bug?extid=deb6abc36aad4008f407
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
>
